Irritable Bowel Syndrome (IBS) Health Center

Tools & Resources

Anticholinergics (Antispasmodics) for Irritable Bowel Syndrome

Guide

Examples

Generic Name

Brand Name

dicyclomine

Bentyl

hyoscyamine

Anaspaz, Cystospaz, Levsin

How It Works

Antispasmodics relax the smooth muscles of
the gut, helping to prevent or relieve painful cramping spasms in the
intestines. These medicines can be taken as needed for cramps. They can also
be taken 30 to 45 minutes before meals that you expect might cause symptoms or
when symptoms would be inconvenient or bothersome.

Why It Is Used

Antispasmodics are used to relieve
cramps or spasms of the stomach, intestines, or bladder.

Do not use antispasmodics if you suffer from:

How Well It Works

Some studies suggest that
antispasmodics improve symptoms of IBS and reduce pain. But studies on antispasmodics available in the United States
have been less promising. Some studies show a benefit, and some don't.1

Side Effects

Side effects may include drowsiness, dry
mouth, blurred vision, or an inability to urinate. Antispasmodics may make
constipation—often a main symptom of IBS—worse.

See Drug Reference
for a full list of side effects. (Drug Reference is not available in all
systems.)

What To Think About

If constipation is your main
symptom, antispasmodics may not work for you. In some cases, use of
antispasmodics can make constipation worse.

If you are pregnant,
ask your doctor about taking antispasmodics. Some studies have suggested that
some antispasmodics can increase the heartbeat of a fetus, and that some are
related to birth defects, though they have not been proved to cause these
defects.